Method of sulfonating an olefin mixture

ABSTRACT

The present invention relates to a method of sulfonating an olefin mixture, in which an olefin mainly consisting of Alpha olefin having 10-20 carbon atoms is admixed with an olefin mainly consisting of an olefin of vinylidene type having 10-20 carbon atoms in such a way as to make the ratio of said Alpha -olefin to said vinylidene type olefin in the aforementioned olefin mixture range between 95:5 and 70:30 by weight, by the use of an inert gas mixture of SO3. It is possible by this method to keep the formation of disulfonates extremely low during the sulfonating process and the olefin sulfonates thus obtained have excellent biodegradability, detergency and foaming effect and, when granulated, a very good preservability and are particularly suited for material for a detergent.

United States Patent Nagayama et al. 1 Jan. 30, 19.73

[54] METHOD OF SULFONATING AN 3,492,239 l/l970 Baumann ct al. ..260/5 l3 R OLEFIN MIXTURE Primary Examiner-Daniel D. Horwitz [75] Inventors: Masuzo Nagayama, Nerima-ku; Anomey woodhams Blanchard and Flynn Hiroshi Okada, both of Tokyo,

Japan 57 ABSTRACT Asslgnee? Fat & Oil y The present invention relates to a method of sulfonat- Japan ing an olefin mixture, in which an olefin mainly con- [22] Filed: 4, 1969 sisting of a-olefin having 10-20 carbon atoms is admixed with an olefin mainly consisting of an olefin of pp 882,339 vinylidene type having l020 carbon atoms in such a way as to make the ratio of said a-olefin to said vinylidene t e olefin in the aforementioned olefin mix- 30 F A l t P t D t YP 1 orelgn pp "on y a a ture range between 95:5 and 70:30 by weight, by the Dec. 11, 1968 Japan ..43/90239 use of an inert gas mixture of S0 it is possible by this method tokeep the formation of disulfonates extrem e- [52] U.S. Cl. ..260/51 3 R ly low during the sulfonating process and the olefin [51] Int.Cl ..C07c 143/02 sulfonates thus obtained have excellent biodegrada- CO 70 143/10, CO 70 143/16 bility, detergency and foaming effect and, when granu- [58] Field of Search ..260/513 R lated, a very good preservability and are particularly suited for material for a detergent. 56 R f C't d l 1 e erences l e 6 Claims, No Drawings UNITED STATES PATENTS 3,544,475 12/1970 Tomiyama et al. ..260/5 l 3 R METHOD OF SULFONATING AN OLEFIN MIXTURE BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to a method of sulfonating olefin having 1020 carbon atoms. In sulfonating a-olefin having 10-20 carbon atoms by the use of an S gas, the quantity of disulfonates formed during the sulfonating process can be limited to a very small amount by introducing an olefin of vinylidene type having 20 carbon atoms into the a-olefin in such a way as to obtain a resultant ratio of a-olefin to vinylidene type olefin in the mixed olefin in the range of from 95:5 to 70:30 by weight and then sulfonating the mixed olefin with an inert gas mixture of S0,. The olefin, sulfonate thus obtained is favorably suited for a detergent material.

2. Description of the prior art a-olefin sulfonates which have 10-20 carbon atoms are now widely used in the manufacture of household detergents because of their excellent detergency, foaming effect and biodegradability. These a-olefin sulfonates are in general prepared by sulfonating aolefins, which are obtained chiefly by means of ethylene polymerization or wax-cracking, with use of an inert gas mixture of 80;. The sulfonated products thus obtained are then hydrolyzed after having been neutralized or neutralized after having been hydrolyzed and they mainly consist of the under-mentioned three components: (A), (B), and (C):

component (A) alkene monosulfonate component (B) hydroxy alkane monosulfonate component (C) alkene disulfonate and hydroxyalkane disulfonate The content of the respective components (A), (B), and (C) in a-olefm sulfonates can be changed considerably by controlling the sulfonating conditions, hydrolyzing conditions, etc.; however, (A) ranges approximately between 40 and 70 percent, (B) approximately between 30 and 40 percent and (C) approximately between 10 and percent. The component (C), that is such disulfonates as alkene disulfonate and hydroxy alkane disulfonate areconsiderably inferior to monosulfonate in their detergency, foaming and other properties as shown in Table l TABLE 1 Comparison of properties of olefin disulfonate and monosulfonate SK-3362 (1955) Relative estimates based on natural soil.

It has also been evidenced that, when incorporated in powder detergents, the disulfonate degrades the stability of the detergents by increasing their hygroscopic properties. Accordingly, it has been desired to keep the content of disulfonate contained in olefin sulfonates approximately to 8 percent or less or, more preferably, approximately to 5 percent or less, to reduce the undesirable nature of hygroscopic property and tackiness and to improve the desirable properties of foaming, detergency, etc. of the detergents. However, it has been extremely difficult to reduce the quantity of disulfonate contained in olefin sulfonates simply by modifying the sulfonating conditions.

For instance, the formation of disulfonate can actually be reduced to some extent by lowering the concentration of S0 which, however, raises a problem that the reaction rate of olefin sulfonation is remarkably reduced.

SUMMARY OF THE INVENTION It is an object of the invention to provide a process for the production of olefin sulfonates according to which the amount of disulfonate contained in olefin sulfonates is minimized.

Another object of the present invention is to provide a methodwhich is not only able to keep the formation of disulfonate very small, but also to obtain olefin sulfonates at a very high rate of sulfonation even by the use of reduced amount of SO in the process.

One further object of the invention is to provide a method of preparing olefin sulfonates which are suited to the manufacture of detergents having excellent biodegradability, foaming effect and detergency.

Still another object of the invention is to provide a method of manufacturing olefin sulfonates particularly fitted for making granular detergents which have an excellent preservability.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventors have achieved this invention by making a discovery that it is possible to control the formation of disulfonate by introducing olefin of the vinylidene type, which may be expressed by the general formula of (where R and R stand for alkyl radicals), into a-olefin. I More particularly, according to the invention, an olefin mixture, which is prepared by admixing an olefin which mainly consists of a-olefin having 10-20 carbon atoms with an olefin which mainly consists of an olefin of the vinylidene type having 10-20 carbon atoms in such a way as to make a ratio of a-olefin to vinylidene type olefin range between 95:5 and :30 by weight (the ratio given hereafter will always be by weight unless otherwise indicated), is sulfonated with use of an inert gas mixture of S0,.

u-olefin, which is manufactured commercially by means of the polymerization of ethylene in the presence of Ziegler catalyst, usually contains vinylidene type olefin, but the content of said vinylidene type olefin is at most several percent, and in this case it is not possible to maintain the formation of disulfonates in olefin sulfonate at a low limit.

According to this invention it is preferable that an olefin which mainly consists of 'a-olefin should have 10-20 carbon atoms, or more preferably 12-18 carbon atoms, which contains more than 85 parts by weight of a-olefin, and which is manufactured commercially by means of wax-cracking or polymerization of ethylene in the presence of Ziegler catalyst.

An olefin mainly consisting vinylidene type olefin which can be used according to the invention should contain more than 70 parts by weight of vinylidene type olefin which may be expressed by the general formula of (where R and R stand for alkyl radicals), and its number of carbon atoms ranges between 10 and 20, or more preferably ranges from 12 to 18. It is dimeric substance of olefin (or dimer olefin) being prepared by means of dimerization of an olefin which has 5 to carbon atoms, or more preferably 6 to 9 carbon atoms, or by means of other methods. Similar to a-olefin, an olefin of this type can by itself be made into a material for detergents by means of sulfonation with the use of an inert gas mixture of S0,. The content ratio of aolefin to vinylidene type olefin in an olefin mixture should usually be in the range of 95:5-70:30, or more preferably in the range of 90:10-70:30. The reason why the content ratio should thus be defined is that, as may be seen from the examples given hereinafter, if the content of the vinylidene type olefin is less than 5 percent of the whole olefin starting mixture, the content of disulfonate contained in the whole sulfonate product would not be less than 8 percent, and if the vinylidene olefin content'is less than 10 percent, the content of disulfonate in the product would not be less than 5 percent.

On the other hand, even in case of increasing the content of vinylidene type olefin to more than 30 percent, the results are that not only much less formation of disulfonate is unexpected but also the sulfonate thus obtained will damage the free flowing property of the prepared granular detergents after having been mixed with builders. a-olefin and vinylidene type olefin are mixed at the ratio mentioned in the foregoing to prepare an olefin mixture and these two types of olefins are then sulfonated simultaneously with the use of an inert mixed gas of S0,.

According to the invention, the sulfonation is conducted with the use of a gas which is prepared by diluting S0, with nitrogen or air to 2-10 percent by volume, or more preferably to 3-6 percent by volume, employing 1.0-1.2, or more preferably 1.05-1.15 mole of SO, per mole of a mixture of olefin, at the temperature ranging from to 120C, (or more) preferably from 40 to 100C.. As for the sulfonator, it is desirable to use a continuous falling film sulfonator.

The sulfonated product thus obtained is neutralized with the use of basic substances, particularly with an aqueous solution of caustic alkali, using temperatures ranging from room temperature to C. and then raising the temperature of the neutralized solution to conduct hydrolysis under the conditions ranging from l7 hours to 200l5 minutes to obtain olefin sulfonates.

According to the abovementioned method it is now possible to reduce the formation of disulfonates in the olefin sulfonates to a low limit as compared with the case where olefin sulfonates are prepared by sulfonating a-olefin alone.

The achievement of these results must most probably be deemed to be due to the fact that, owing to a competitive reaction which takes place between the aolefin and the vinylidene type olefin in the course of simultaneous sulfonation reaction occurring between the a-olefin and the vinylidene type olefin, vinylidene type olefin starts to react selectively earlier than aolefin in its early stage of reaction and the resultant vinylidene olefin sulfonic acid acts as a buffer agent in the fierce reaction which takes place between a-olefin and S0 By means of such effects, the rate of the sulfonating reaction of 'a-olefin can be maintained until its completion and it has also been made possible to obtain sulfonated products in which the content of disulfonate is small due to the mild reaction in the early stage of the sulfonating reaction. And it is also noticed that the optimum reaction temperature required for the simultaneous sulfonation of both a-olefin and vinylidene type olefin is lower than that required for the sulfonation of a-olefin alone by several degrees centigrade and it can readily be imagined that the low reaction temperature has a favorable influence upon the desired low formation of disulfonates.

According to the present invention, it has been made possible to keep down the formation of disulfonate in olefin sulfonate at an extremely low level and also to maintain the reaction temperature lower and to decrease the consumption of SO, as compared with the case where .a-olefin alone is sulfonated. Detergents made from olefin sulfonates thus prepared have excellent foaming effect and detergency and they are not only excellent in their preservability when prepared in the form of granules but also show excellent properties when made into liquid detergents or when used in other types of detergents.

The invention will be further described with reference to the following experimental test and examples; however, this invention is not intended to be limited by the details set forth in these experimental test and examples.

EXPERIMENTAL TEST Olefin mixtures were prepared with a-olefin 'and vinylidene type olefin mixed at various ratios as set forth below, both being free from impurities, and the mixtures were sulfonated by the use of a continuous thin film sulfonation unit designed on a laboratory scale as mentioned below. The reaction unit is made of Pyrex glass having an inside diameter of 5 mm and equipped with a reaction zone having a length of 120 cm, in which an olefin mixture and S are made to flow downwardly continuously in parallel to come in contact with each other. Reaction conditions are: the concentration of S0 2.8 vol. percent (diluted with nitrogen gas), the contact time 30 seconds, the rate of olefin feeding 6 ml/min., the temperature of olefin mixture 30C.

Incidentally, the mole ratios of SO /olefin and the reaction temperatures used in the experimental tests are as per conditions indicated in the following table.

The various sorts of sulfonates thus prepared were neutralized respectively with use of a 10% NaOH aqueous solution so the respective solution would become equimolar with S0,, which had been introduced at the time of sulfonation, and then were hydrolyzed at 160C. for 20 minutes to obtain olefin sulfonic acid-Na. Property analyses were made of olefin sulfonic acid-Na thus obtained after it had gone through process of dealkalization and removal of oils not reacted and Glaubers salt, whose results are shown in Table 2.

TABLE2 Sulfonating Reaction Conditions and Analytical Properties of Sulfonated Products Prepared from Olefin Mixtures Having Various Mixing Ratios of a- Olefin to Vinylidene Olefin Component S0,] Reaction Conver- Disulfonof Olefin Temperasion ate in the Mixture mole ture Ratio Sulfonate (wt ratio (C) (wt A0 V0 100 0 1 .20 50 96.2 16 100 0 1.15 50 92.0 12

Notes: A0 and V0 stand for a-olefin and vinylidene type olefin respectively.

SOJolefin mole ratio and the reaction temperature required for obtaining the maximum reaction percentage and color tone of sulfonate.

It can be noticed from Table 2 that:

1. In case where a-olefin alone is used as a material, the reaction percentage decreases remarkably when an attempt is made to decrease the quantity of disulfonate.

2. The formation of disulfonate can be kept down below 8 percent without decreasing the reaction percentage when more than 5 percent of vinylidene type olefin is contained in the olefin mixture; however, the formation of disulfonate no longer decrease when more than 30 percent of vinylidene type olefin is present.

EXAMPLE 1 with SO which had been diluted to 5 percent with use of air by letting the former flow down in the form of thin film through a vertical standing pipe and the latter pass through the pipe flowing in the same direction. The mole ratio of olefins to SO was 1:1.15 at that time. The sulfonated product thus obtained was immediately (within 5 minutes) neutralized with use of caustic soda solution equimolar to SO existing in the product at the temperature ranging from 50C to 60C. The temperature of the mixture was raised to 160C. which was maintained for 20 minutes and the mixture was then cooled to 50C. or below. Disulfonate contained in olefin sulfonate thus obtained was 8%.

EXAMPLE 2 a-olefin having 12-16 carbon atoms (containing 3.2 percent vinylidene type olefin) manufactured commercially by polymerizing ethylene in the presence of Ziegler catalyst was admixed with the same dimerolefin as used in Example 1 in such a way as to make the ratio of a-olefin to vinylidene type olefin :25. The olefin mixture was then made to flow in the thickness of 0.02 mm at the rate of 5.58 kg/min. down on the wall of the cylinder of a sulfonating apparatus (here the cylinder is made to allow water runthrough), which is designed to let the olefin mixture fall down in a predetermined thickness by overflowing from the top of the cylinder. At the same time, an SO (gas) was made to flow at the rate of 2.44 kg/min in gaseous phase following the direction of the olefin mixture. The gaseous SO gas used in this case was diluted to 3. percent by volume with use of the air. The flow rate of the gas within the cylinder was 24 m/sec. During this process, the reaction heat was made to be absorbed by the quenching water to keep the reaction temperature between 45 and 47C., and the gauge reading of the pressure was maintained at 0.8 kg/cm The time of contact established between the gas and the solution was 6 minutes. The sulfonated products were then put into a tank equipped with a mixer and was stirred at 30C. for 15 minutes. To the reaction products-thus obtained at 13% solution of caustic soda .was added at the rate of 6.57.kg/min (using 0.7 mole per 1 mole of S0 and was heated at. 160C. for 10 minutes by the use of an autoclave and then cooled. The amount of disulfonate contained in olefin sulfonate thus obtained was 4.3 percent. I

What we claim is:

1. In a method for preparing a mixture of a-olefin monosulfonates and dimer olefin monosulfonates, said mixture containing less than about 8 percent by weight of by-produced disulfonates, comprising the steps of sulfonating a starting olefin mixture with SO gas diluted with inert gas, and then hydrolyzing and neutralizing the sulfonated olefin mixture, theimprovement which comprises, effecting the sulfonation step by reacting at a temperature in the range of from 20 to C,

A. a starting olefin mixture consisting essentially of (l) a-olefin having 10 to 20 carbon atoms and (2) vinylidene olefin of the formula wherein R and R are allt yl radicalsand the total number of carbon atoms in the vinylidene olefin is in the range of from 10 to 20, the weight ratio of (l) to (2) in said starting olefin mixture being in the range of 95:5 to 70:30, with v B. 1.0 to 1.2 mols of SO gas per mol of starting aolefin mixture, said SO, gas being diluted with an inert gas to an So concentration of from 2 to percent by volume.

2. A method according to claim 1 wherein said ratio of a-olefin to vinylidene type olefin in the olefin mixture ranges from 90:10 to 70:30 by weight. 7 I

3. A- method according to claim 1, wherein sulfonasulfonator. 

1. In a method for preparing a mixture of Alpha -olefin monosulfonates and dimer olefin monosulfonates, said mixture containing less than about 8 percent by weight of by-produced disulfonates, comprising the steps of sulfonating a starting olefin mixture with SO3 gas diluted with inert gas, and then hydrolyzing and neutralizing the sulfonated olefin mixture, the improvement which comprises, effecting the sulfonation step by reacting at a temperature in the range of from 20* to 120* C, A. a starting olefin mixture consisting essentially of (1) Alpha -olefin having 10 to 20 carbon atoms and (2) vinylidene olefin of the formula wherein R and R'' are alkyl radicals and the total number of carbon atoms in the vinylidene olefin is in the range of from 10 to 20, the weight ratio of (1) to (2) in said starting olefin mixture being in the range of 95:5 to 70:30, with B. 1.0 to 1.2 mols of SO3 gas per mol of starting Alpha -olefin mixture, said SO3 gas being diluted with an inert gas to an SO3 concentration of from 2 to 10 percent by volume.
 2. A method according to claim 1 wherein said ratio of Alpha -olefin to vinylidene type olefin in the olefin mixture ranges from 90:10 to 70:30 by weight.
 3. A method according to claim 1, wherein sulfonation is conducted maintaining the mole ratio of olefin mixture to SO3 gas at 1.05-1.15.
 4. A method according to claim 1, wherein sulfonation is conducted at a temperature ranging from 40*C to 60*C.
 5. A method according to claim 1, wherein sulfonation is conducted using an inert gas mixture of SO3 which is prepared by diluting SO3 to 3-6 percent by volume with use of an inert gas. 